Jintanat AnanworanichBernard HirschelSunee SirivichayakulSasiwimol UbolyamThidarat JupimaiWisit PrasithsirikulPloenchan ChetchotisakdSasisopin KiertiburanakulWarangkana MunsakulPhitsanu RaksakulkarnSomboon TansuphasawadikulMalte SchutzWendy SnowdenKiat RuxrungthamThe HIV Netherlands Australia Thailand Research CollaborationHopitaux universitaires de GeneveChulalongkorn UniversityBamrasnaradura Infectious Disease InstituteKhon Kaen UniversityMahidol UniversityVajira HospitalSanpatong HospitalBuddhachinnaraj HospitalHoffmann-La Roche Inc.Roche Products Limited UK2018-08-202018-08-202006-08-30Antiviral Therapy. Vol.11, No.5 (2006), 631-635135965352-s2.0-33747766878https://repository.li.mahidol.ac.th/handle/20.500.14594/23641Background: There are few data on the selection of resistance by ritonavir-boosted saquinavir (SQV/r), particularly in antiretroviral (ARV)-naive patients. Objective: To assess the incidence of virological failure and evolution of resistance in ARV-naive individuals receiving SQV/r in the induction phase of the Staccato trial. Methods: ARV-naive subjects (n=272) received SQV/r 1,600/100 mg once daily with two nucleoside reverse transcriptase inhibitors (NRTIs) for at least 24 weeks. Patients were defined as having virological failure (VF) when there were two consecutive HIV-1 RNA measurements >500 copies/ml after week 12. Viral genotypes (reverse transcriptase [RT] and protease [PRO]) were determined at baseline in all patients and as close as possible to the time of initial failure in patients experiencing VF. Results: VF was observed in 9/272 patients receiving SQV/r 1,600/100 mg once daily with two NRTIs (3.3%) and occurred 19-48 weeks after treatment initiation. Eight of these patients were evaluable at failure. No major PRO mutations were detected, but 2/8 displayed single new minor PRO substitutions (M36I, L1OI) at VF that were known or suspected not to have been present at baseline; both these substitutions exist as natural polymorphisms. A third patient displayed a single new RT mutation (M1841). Conclusions: SQV/r plus two NRTIs (1,600/100 mg once daily) is an effective initial treatment option for ARV-naive patients, resulting in a low rate of viral rebound (3.3%). Furthermore, no major protease mutations were detected following VF, suggesting that future treatment options are preserved. © 2006 International Medical Press.Mahidol UniversityMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS